A typical flue gas desulfurization (FGD) system 100 is shown in FIGS. 1A-1B. The system 100 includes a FGD unit 102 that uses an upward flow (fluegas) and a spray or tray tower with a centering outlet cone 110 and a single discharge hood 120. The fluegas exits the FGD unit 102 through a centered outlet 110 and flows past a 90 degree bend 112 and hood 120 before flowing through an expansion joint 130 and entering the stack 140. Steel supports 150 are used to support the discharge hood 120, and are also used to support optional CO2 capture systems (not shown) disposed downstream of the FGD unit 102.
U.S. Pat. No. 5,648,048 to Kuroda, et al. discusses another example of a FGD unit having a single outlet duct supported by a circulation tank disposed beneath the outlet duct. However, in Kuroda and all prior art devices known to Applicants, FGD units with multiple outlets require separate structural support 150 apart from the FGD unit 102 to support the outlets, which is expensive, takes up a lot of space, and adds pressure drop. Kuroda and all other extrinsic materials discussed herein are incorporated by reference in their entirety. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
FIG. 2 illustrates another embodiment of a prior art FGD system 200 having two CO2 capture systems 240 disposed downstream of a FGD unit 202. The addition of the CO2 capture systems 240 adds complexity to the system 200 since the gas exits the top of the FGD unit 202, and is directed through a centering cone 204 to ductwork 210 that connects to the stack 230 and has additional ductwork 220A and 220B and dampers 222A and 222B that allow the gas to flow to the CO2 capture systems 240. Ductwork 210 can also include a damper 212, which adds further weight to system 200. The ductwork 210, damper 212, and CO2 capture systems 240 require separate structural support (not shown) to support these components.
Thus, there is still a need for post-combustion conditioning systems having outlet ducts that are substantially supported by a flue gas conditioning device.